


Heartseed Havoc

by DarkAkumaHunter



Category: Harry Potter - J. K. Rowling, ココロコネクト | Kokoro Connect
Genre: Crossover, Gen, Order of the Phoenix AU
Language: English
Status: In-Progress
Published: 2016-12-15
Updated: 2017-02-10
Packaged: 2018-09-08 17:16:23
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,255
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8853751
Author URL: https://archiveofourown.org/users/DarkAkumaHunter/pseuds/DarkAkumaHunter
Summary: What starts as a body-swapping fiasco slowly draws together two opposing forces as they fight to find a new normal and a sense of stability in a life that is spiralling out of their control.
Will have slow updates.
(you don't need to know anything about kokoro connect to read this)





	1. I - I

**Author's Note:**

> So I binge watched Kokoro Connect the other day and somehow decided it sounded like a great premise to play around with. There will be no characters from the show aside from Heartseed - this is entirely about Heartseed messing with some wizards and the outcome that brings about. I haven't read it, so I'm only familiar with it from Hito Random through Michi Random, which is what stuff is going to go down. I'm only using the premise (Heartseed and the phenomenon) and not the detailed plotline of KC, so no need to worry about all that.
> 
> Follow my new writing [tumblr](http://aj-writes-fic.tumblr.com/) for progress updates and fic chat.

Given the chaos that had become of their summer break, Hermione had known better than to have high hopes for the year to come. Being named Prefect had simply been one small candle-flame of light in the murky uncertainty of going forward into a world that refused to see reason, ruled by a government content to stick their heads in the sand. So she had been upset, yes, when their new Defence Against the Dark Arts teacher turned out to be a horrid, Ministry-appointed shrew, but in the grand scheme of things she’d felt that she really should have seen it coming.

This, however, was not something she ever could have predicted.

It started slowly, unobtrusively, and then it happened all at once.

Hermione ignored it at first.

_She opened her eyes to darkness. It wasn’t the first time Hermione had woken somewhere in the middle of the night, and she doubted it would be the last, but it took her a moment to realise that something was wrong. Night-time or no, it was_ too dark _. She never pulled the hangings on her bed all the way closed, and the moon outside the window in the girls’ dorm always offered a hazy light, however dim, to her surroundings. But she could barely see the shadowy outline of her own hands in front of her face._

_Frowning, Hermione groped about the darkness around her until her fingers found the fabric of the curtains. They curled in the fabric, ready to tear it open, but she paused, rubbing it gently between finger and thumb. It was softer than she remembered it being. Almost… silky. But that was ridiculous. They wouldn’t change the curtains in the middle of the night._

_She breathed out a laugh – careful of her volume since Lavender was an unpredictably light sleeper. There was something about the dark that made her paranoia skyrocket, even in the relative safety of her own bed._

_“Don’t be silly Hermione,” she whispered to herself, but her voice sounded strange. Unfamiliar. Her fingers tightened in the silken curtain. She would go to the bathroom, wash her face, and try to get some more sleep before having to stumble through a new day of heightened tension in the Gryffindor common room._

_The dorm, when she pulled back the curtain, was darker than it should have been. Her gaze automatically sought out the window, wondering if a particularly bad storm had rolled in after she went to bed, but the window wasn’t there. Instead, she found a single light source – a small wall sconce above a door that wasn’t where she’d expected it to be, which held a wavering ball of soft, pale blue fire. It gave off just enough light for Hermione to make out the shapes of more beds, and, if she squinted, the dark shapes of trunks._

_Nothing was where it was supposed to be._

_Still, if she had learned anything in her four years at Hogwarts it was the courage to do a bit of investigating when things stopped making sense (more so than usual, in a school of magic, at any rate)._

_The temperature dropped the moment she stepped out of the confines of the bed. It wasn’t_ uncomfortably _cold, but it was a noticeable change. Her dorm was never this cold,_ particularly _not in September._

_Careful to keep her wits about her, she tiptoed carefully towards the lit doorway, trying to ignore the feel of unfamiliar carpet beneath her bare feet. The door, thankfully, led to a bathroom, and not a hallway. It was dark inside, but when she closed the door gently behind her a number of the same blue flames burst into life around the room, letting Hermione see properly for the first time since opening her eyes._

_She headed straight for the large, ornate mirror that hung above a pair of sinks with fancy silver taps. If it was an enchanted mirror like the ones she’d first encountered in the Leaky Cauldron, it was currently asleep. The face that stared back at her from the glass was quite definitely not her own. Dark hair, pale skin, and cold eyes. It wasn’t an entirely unfamiliar face, but Hermione couldn’t for the life of her put a name to it. All she could say with any certainty was that the bewildered look she currently wore was one that likely very rarely – if at all – appeared on the aristocratic features she was suddenly in possession of._

_Hermione stayed in the bathroom for nearly quarter of an hour, staring, thinking, trying to reach the trickle of memory that said she knew exactly whose face she was wearing, and then, when she failed to reach a conclusion, she tiptoed back to the bed, pulled the curtains shut, and forced herself to go back to sleep._

Because the next time she’d opened her eyes she had been back in her own bed in Gryffindor Tower, it had been simple enough to put it behind her as an unusually lucid dream. Hermione had never had a lucid dream before, and it was odd that she remembered so many of the details, even the day after, but what else _could_ it have been?

Then, two days later, it happened again. A foreign bed, unfamiliar surroundings. A dream, surely. She didn’t leave the bed that time – didn’t want to know if it was the same person she was dreaming of, or someone else again – and lay still with her eyes closed until she eventually succumbed back to sleep.

Only this time, when she woke up, things were different.

She was back in her own bed, in her own body, yes, but when she was brushing her hair before breakfast Lavender kept sending her odd, fleeting glances.

“Is there something on my face?” Hermione asked, her eyes on her hands as she worked through a particularly stubborn knot.

“No.”

She glanced across the room. Lavender had stopped pretending she wasn’t watching her, and stared with a strange look on her face.

“This may be an odd question but… do you sleepwalk sometimes?”

At that Hermione abandoned her hairbrush and spun to face Lavender, eyebrows furrowed in confusion.

“Not to the best of my knowledge… Why? Did something happen?”

“Maybe? I’m… not so sure anymore.” She shrugged, as though to brush it off, but Hermione wasn’t about to let her off the hook without explaining.

“It’s fine if you’re not sure. Just tell me what you think happened.”

“If you insist.” She started doing her own hair as she spoke, so as to avoid maintaining eye contact the whole time. “You know I’m a light sleeper, but I also sort of take forever to wake up, so, it might just have been my imagination. But. I woke up last night because I thought I heard someone moving about in the dorm. And I saw you going through your trunk and your bag in the dark – I have no idea what you might have been looking for – and also maybe cursing? I think you were muttering to yourself anyway, but I couldn’t tell what you were saying. You slammed your trunk shut – I’m sort of surprised it didn’t wake anyone else up – and then you went to the bathroom and I fell asleep again.”

“Huh.” Hermione glanced over at her trunk. It _had_ seemed a bit messier than she’d left it, but she had thought that was just her imagination. “It was just a dream,” she told Lavender, hoping she sounded convincing, and that her smile won out over the frown that wanted to drag her lips down.

Lavender laughed a little, not meeting her gaze. “Right? I mean, we’ve been sharing a room for four years and you’ve never sleep walked before. Why would you suddenly start now?”

Neither of them had an answer for that. Lavender hurriedly left the room while Hermione fell into a contemplative silence.

She’d had a body-switching dream last night. Someone had been through her stuff. That would imply that it was less of a dream and more of a reality. But that was _ridiculous_. Wasn’t it? Magic was crazy and defied all sorts of natural laws, but surely it couldn’t instigate _spontaneous body-switching!_

“Be rational,” she chided herself. She slapped her cheeks gently for good measure.

As she threw her hair up into a messy bun she made a decision. She didn’t have class first period, so she would grab something for breakfast and then make tracks for the library. There was (almost) nothing a good round of research couldn’t help with.

Neither Ron nor Harry were in the common room when she came down from the dorm, so they were either still asleep (lazy) or had gone on without her (because no one could get between Ron and food), so she headed out for the Great Hall by herself.

The path she took was relatively quiet – most of the Gryffindors were probably already in the Great Hall – and she allowed her thoughts to drift as her feet paced the familiar corridors. It was because she was swept away in planning out a start point for her research that she didn’t immediately react when a hand grabbed her wrist and started tugging rather forcefully.

She was in an abandoned classroom before she could do more than hiss out a sound of pain and surprise. Her mysterious assailant let her go once she was inside and shut the door behind them, murmuring a quiet locking charm. Hermione spun with a glare, fingers reaching for her wand and an irate reprimand on the tip of her tongue, but when she saw who had grabbed her she froze.

In front of her, a frosty but determined look settled across a pale, aristocratic face, stood the girl Hermione had seen in the mirror. The green of her tie sent alarm bells ringing but her name was suddenly just within reach.

Hermione didn’t know what to say, but thankfully the Slytherin girl did.

“Granger, we need to talk.”


	2. I - II

**Summary for the Chapter:**

> Daphne has a reoccurring dream which isn't a dream, and plans are made.

**Notes for the Chapter:**

> This story is going to jump POVs a LOT, but only from chapter to chapter.

Daphne knew something was amiss immediately.

She was well aware of the fact that, for as long as she could remember, she had never once dreamed in her sleep (or, at least, never had a dream that she had even the faintest remembrance of upon waking). Therefore, when she opened her eyes in an unfamiliar bed, in an unfamiliar room, she could say with absolute certainty that it wasn’t just a dream.

It had happened once before, just a few days ago if she remembered correctly, but at the time she’d been in an absolutely dreadful mood and had had no desire to leave the warmth of even unfamiliar sheets to find an explanation when she could have been sleeping instead. This time she had no such qualms.

Daphne eyed the burgundy bed-curtains with distaste before drawing them fully open. The room she was exposed to was lighter than she was used to, having spent four years in the dungeons, where the only natural light that reached them was filtered through the lake.

“This place is a mess,” she muttered to herself as she picked her way over to the window. The Fifth Year Slytherin Girls’ Dorm was always immaculate, but here things were strewn haphazardly all around the room.

If she was still in Hogwarts (the ideal situation), and not somewhere beyond the scope of her day to day life (a terrifying thought given the circumstances), then she had a pretty good idea of where she was. The window meant she was above ground, which left two possibilities: the Ravenclaw or Gryffindor Towers. The bed-curtains, however, screamed Gryffindor.

There were things scattered across the windowsill too, so Daphne contented herself with leaning towards the glass and staring out at the night sky. Outside of the shorts months spent away from Hogwarts, she only ever got to see the sky like this during Astronomy class. It was one of the downsides of being in the dungeons.

When she was finished indulging herself she turned back to the bed she had awoken in. It was technically the tidiest space in the room, if only because the mess consisted of haphazard book stacks both at the head of the bed and around the trunk at the base, instead of an alarming myriad of personal belongings scattered so that Daphne couldn’t even begin to guess which things belonged to the owner of which bed.

Gryffindors truly were a totally different breed.

Given that the last time something like this had happened Daphne had chosen to steadfastly ignore it and simply go back to sleep, she didn’t have anything even close to an accurate frame of reference as to how long this… _switch_ had lasted. If she wanted to at least figure out _who_ was involved in this then she couldn’t afford to muck about.

With light steps Daphne returned to the bed, skirting the mess to kneel at the end. The trunk which sat at the foot of the bed wasn’t visibly locked, but a messenger bag sat open atop it; hopefully she would be able to find answers in there, and not have to mess with any potential locking or anti-theft charms on the trunk.

Her hopes were quickly dashed. There were no conveniently finished essays, signed and waiting to be handed in residing in the bag. It was mostly blank parchment, quills, and an ink vial or two. The textbooks were in one of the piles beside the trunk, but, although they _did_ have their owner’s initials inside the front cover, the letters meant nothing to Daphne, who barely knew the last names of all the Gryffindors in her year, let alone their first and middle names – and this might not even be a fifth year dorm! (The textbooks would suggest _that_ particular fear was unwarranted, but it would really be just her luck if it turned out to be true.)

With a sigh Daphne dumped the bag on the floor and turned her attention to the trunk.

Usually, if she were to engage in a bit of snooping, she would invest in more than a few detection charms. If this was an upper-year dorm as she suspected then it was hardly inconceivable for there to be protection charms on the trunks – in Slytherin that was a given. But Daphne didn’t have her wand, nor did she know where her current host kept _her_ wand while she slept, nor did she think that, even were she to find it, it would work all that well with her body out of sync. That meant there were no options open to her other than to charge straight in.

“If this blows up in my face I will have vengeance,” Daphne vowed seriously, touching cautious fingers to the trunk’s lid. She gave a gentle tug upwards, and the lid moved with little resistance. Her earlier observation had been correct: it wasn’t locked. At all.

When it was sitting fully open and Daphne could confirm she hadn’t set off any sort of alarm or ward she rolled her eyes at her own paranoia. “Gryffindors,” she muttered distastefully. “No sense of danger.”

There were, surprise surprise, more books inside the trunk, though only a few, and these looked more personal – notebooks or journals or something of the sort. She picked up one and flicked briefly through it, but the writing was… _strange_ , somehow, obviously not written by quill, and she wasn’t in the mood to decipher whether or not it was someone’s diary.

Digging through robes and casual clothes and more parchment, Daphne finally spotted something potentially useful: a photo album. The pictures on the first few pages were immobile – muggle photographs. She’d switched with a muggleborn. She wrinkled her nose at the unmoving photos, but peered closer, trying to see if she could recognise anyone. They were older photos though, and Daphne quickly gave up and flicked through until she found some that moved.

When her gaze landed on a shot of a trio of Gryffindor students she dropped the album on the floor. A feeling of dread washed over her and she groaned. She knew _exactly_ whose body she was temporarily stuck in.

Shoving the album back into the trunk she slammed the lid shut and jumped to her feet. She needed to confirm it with her own eyes. She scanned the dimly lit room and, after locating a door she guessed led to a bathroom, she dashed towards it, shutting the door quickly behind her.

Light flared into life in several wall sconces as she inched towards the mirror set over the sink. This was her last chance to back out and pretend it never happened. But Daphne was no coward, and she needed answers.

The face in the mirror was one familiar to her – to all in her year, likely. Bushy brown hair hung about her face, messy from sleep. She was officially one third of the abhorrent Gryffindor trio that always somehow managed to be the centre of attention every year.

She was standing in Hermione Granger’s body.

**oOoOo**

When Daphne woke up back in her own body she knew there was only one thing for it. Once was terrifying, twice was more than a little alarming, and if it was going to happen a third time she needed to try and get a handle on it, as best she could. That meant confronting Hermione Granger.

Charging in headfirst without any of the details was rather outside of her comfort zone, but sometimes you simply needed to draw on your inner Gryffindor for the sake of self-preservation.

Daphne was naturally an early riser, so she was out of the dorm before anyone else was even near coherent enough to wonder what she was up to. They weren’t obvious about it but, when they were in the mood, Slytherins could be just as incurably curious as any Ravenclaw, and Daphne was in no mood to explain her sudden desperate need to ambush Gryffindor’s resident Brainiac to the likes of Pansy Parkinson.

She dropped by the kitchen – the entrance to which was a badly kept secret amongst the two houses located in the lower castle – and grabbed a few slices of toast for breakfast before heading off to start her stakeout.

Daphne settled into an alcove along a corridor on the first floor, a location she knew was one of the main routes from higher up in the castle to the Great Hall. There was, of course, a chance that Granger would go a different way, but the day was only just beginning – if the first attempt failed then she would try and try again. There was no way this could be settled without talking face to face, and if it took her all damn week to corner the girl then she would do it.

Thankfully it appeared that luck was on her side.

Several larger groups of red and gold had already passed through the corridor, and Daphne was just starting to think that perhaps she’d be better off heading back to the Great Hall herself before anyone started asking questions, when she spotted Granger’s lone figure meandering towards her. The girl was obviously lost in thought, and Daphne used that to her advantage as she passed by her little alcove, stepping out behind her and grabbing her wrist in an iron grip.

Granger barely gave more than a small squeak of surprise as she found her course suddenly reversed, following Daphne with surprisingly little resistance as she tugged the Prefect towards the nearest classroom.

Once inside Daphne relinquished her grasp on Granger’s wrist, giving her a little shove further into the room as she let go, and turned her attention to warding the door to prevent any inconvenient interruptions. Only once she was satisfied did she turn back to Granger. The girl froze under her gaze, caught somewhere between yelling and cursing her, wand clenched tightly in hand.

The likelihood of her actually going through with an unprovoked curse, based on her personality, was low, so Daphne ignored the wand pointed at her in favour of what she had come here for. Conversation.

“Granger, we need to talk.”

Granger was silent for a long moment, seeming more bewildered than Daphne had ever seen her. Then, she lowered her wand.

“You… I… I know your face!” she said somewhat frantically, a sudden outburst in the still quiet of the room.

“Good,” Daphne replied in a deadpan tone. “We’ve only been in the same potions class for four years now.” She knew from Granger’s face that it wasn’t what she meant, but that didn’t mean she had to let her get away with such an ambiguous and potentially insulting remark.

“That’s not— I don’t—” Granger bit her lip, closed her eyes, and inhaled deeply through her nose. When she exhaled she was frowning, but calmer.

“I _meant_ that, well, I would say this might sound crazy but since _you_ came to _me_ and not vice versa it might not be as hard to believe as I expected. Still, I could be wrong.” Her expression became a little desperate here, as though she were begging Daphne to tell her that whatever was happening was just a hallucination. “I’ve been having…”

“Body-switching dreams,” Daphne finished for her. She knew without asking that neither of them truly believed they were dreams, but it felt just a little less crazy to tack ‘dreams’ onto the end of the statement rather than ‘episodes’.

Granger groaned at her answer, burying her face in her hands.

“It’s only the second week of term,” she commented rather despairingly. Daphne side-eyed her with what she would never admit was a smidge of concern.

“Out of everything about this there is to be worried about, you’re concerned about the _timing?_ ”

“Oh. Well.” She shrugged, although she looked a little frazzled. “Granted, this is all pretty weird—”

Daphne mouthed the word “weird” in disbelief – it didn’t feel like an adequate description.

“—but weird stuff has happened to or around me every year since I started this school. And, okay, sure, getting petrified is a little different to sporadic, spontaneous body-switching, but that just makes it a Weird Thing. So I’m not surprised that _something_ happened – I’m starting to feel like it’s inevitable – it just never happens this _early_.”

“You—” Daphne sighed. She’d never been one to put much stock in student gossip, but suddenly a lot of things seemed to make sense. Of _course_ those reckless Gryffindors would get themselves caught up in all sorts of nonsense. She knew that she definitely didn’t want to know any of the details. The current fiasco was more than enough to be getting on with.

“None of that’s important,” she said dismissively. Granger frowned at her tone, but didn’t refute the statement. “What’s important is what’s happening _right now_. I don’t know why, and you don’t know why, and that needs to change. Soon. If there’s even the slightest chance that this could continue on indefinitely, then we need to figure out how to stop it. We’ve been lucky so far that both times have been during the night, but it would be naïve to assume that it’s limited to a specific time of day.”

“You’re right,” Granger muttered. “Why didn’t I think of that?” There was a look on her face that Daphne was used to seeing on Blaise whenever an answer escaped his grasp – a look that meant a trip to the library was imminent.

Truly, Ravenclaws, the lot of them.

“Our timetables likely don’t align, and it would be unwise to be seen together more than necessary, so we will have to research separately,” Daphne pointed out, hoping to finish this talk before Granger tore out of the room for the library as she so obviously wanted to. “That being said, we will have to compare notes to make sure we aren’t wasting our time and reading the same books. Do you know of anywhere out of the way where we could meet?”

Granger glanced at her, then around the room they were currently standing in. It was dusty by Hogwarts standards, with only a couple of desks and a partially smashed blackboard pushed into the corner.

“Why not here?” she offered.

Daphne folded her arms uncertainly. It was hardly _ideal_ , but it _was_ an abandoned classroom, so the likelihood of anyone save one of the castle’s resident ghosts walking in on them was incredibly low. Given time Daphne was sure she could come up with something more palatable, but for right now…

“Fine. Two days from now, after dinner, we meet here. Whatever books you find between now and then, you go A-M, I’ll go N-Z. That way we won’t overlap.”

“Agreed.” Her gaze swept to the door and Daphne sighed, cancelling the enchantments with a wave of her wand. She walked past Daphne, but paused with her hand on the doorknob. “Greengrass, I promise I’ll be careful.”

Daphne wasn’t sure what to make of her parting words as Granger swept out of the room without looking back. She wasn’t sure what to make of anything at the moment.

“We’ll sort this out,” she whispered to herself before leaving the classroom. “That Brainiac is on the case, she’ll solve it in no time.” Nodding determinedly, she erased any inkling of uncertainty from her face, and ventured off towards her first class.

Hopefully no more variables would be thrown into the mix before they could find an answer.


End file.
